Storage stable premixed hydraulic cement compositions, cements, methods, and articles

Inventors

Engqvist, Håkan • Aberg, Jonas

Assignees

Ossdsign AB

Abstract

Refrigerated hydraulic cement compositions comprise a mixture of (a) β-tricalcium phosphate powder, (b) monocalcium phosphate comprising monocalcium phosphate anhydrous (MCPA), monocalcium phosphate monohydrate (MCPM), or a combination thereof, wherein a 0.1 g/ml saturated aqueous solution of the monocalcium phosphate has a pH less than 3.0, (c) non-aqueous water-miscible liquid, and (d) an aqueous hydrating liquid. The aqueous hydrating liquid is included in an amount of about 1-50 volume percent, based on the combined volume of the non-aqueous water-miscible liquid and the aqueous hydration liquid, and the refrigerated hydraulic cement composition is storage stable for greater than one day, without setting. Methods of forming hardened cements in vivo and/or for forming implants for use in vivo employ the hydraulic cement compositions.

Core Innovation

The invention provides a refrigerated hydraulic cement composition including β-tricalcium phosphate powder and monocalcium phosphate comprising monocalcium phosphate anhydrous (MCPA), monocalcium phosphate monohydrate (MCPM), or a combination thereof. The monocalcium phosphate is characterized such that a 0.1 g/ml saturated aqueous solution of the monocalcium phosphate has a pH less than 3.0. The composition further includes a non-aqueous water-miscible liquid and an aqueous hydrating liquid.

The refrigerated hydraulic cement composition is refrigerated at a temperature not greater than about 5° C., and is storage stable for greater than one month without setting. The composition is configured to form Monetite (CaHPO4) upon hardening at a temperature of about 35–100° C. The aqueous hydrating liquid is included in an amount of about 1–50 volume percent based on the combined volume of the non-aqueous water-miscible liquid and the aqueous hydration liquid.

The described formulation approach uses refrigeration to inhibit setting during storage and uses subsequent warming to enable hardening. The partial content indicates that warming enables hardening to Monetite and/or Brushite depending on conditions, while refrigeration yields storage stability without setting. The composition and preparation/manufacturing sections further describe verification of Monetite-forming implants using XRD and SEM.

Claims Coverage

The partial content identifies one independent claim (clm-00001) defining the core refrigerated hydraulic cement composition and its storage and hardening behavior, with dependent claims that further specify component identities, pH, relative amounts, and particle/grain size ranges, and that extend to a manufactured article using a refrigerated container.

Across the independent claim and its dependents indicated in the partial content, the inventive focus is the combination of β-tricalcium phosphate with an acidic monocalcium phosphate (pH <3.0 for a 0.1 g/ml saturated aqueous solution), a non-aqueous water-miscible liquid together with an aqueous hydrating liquid in about 1–50 vol%, and refrigeration at ≤5° C. to achieve storage stability without setting, followed by hardening at about 35–100° C. to form Monetite (CaHPO4).

Stated Advantages

Documented Applications